Saddlebacking - the term for the phenomenon of Christian teens engaging in unprotected anal sex in order to preserve their virginities. Named after Saddleback Churh, home of the Reverend Rick Warren, who is a proponent of abstinence education, the "sex ed" that has convinced so many Christian girls and boys that buttfucking isn't actually sex.

Saddlebacking - After attending the Purity Ball, Heather and Bill saddlebacked all night because she's saving herself for marriage.

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The action of performing anal sex in order to preserve ones vaginal purity. Most extreme religious couples practice this before marriage, although in almost all religious publications this is looked up as a worse offense.
In the case of homosexual relations, this is the only way for a men to perform intercourse with each other.

"Have you heard that Tom and Bill have a dry-erase board in their bed room?"
"No, whats it for?"
"I have heard that is used to keep score of who has had the most orgasms while they are saddlebacking each other. I also heard that they participate in the convergence practice after they finish."